USGS Water-Year Summary 2023
05559600 ILLINOIS RIVER AT CHILLICOTHE, IL
LOCATION - Lat 40°55'45", long 89°27'42" referenced to North American Datum of 1927, in NW 1/4 NE 1/4 NW 1/4 sec.22, T.11 N., R.9 W., Peoria County, IL, Hydrologic Unit 07130001, at center of Atchison, Topeka and Sante Fe Railroad bridge, 1 mi north of Chillicothe and at mile 181.9.
DRAINAGE AREA - 13,717 mi².
WATER-QUALITY RECORDS
PERIOD OF RECORD -
SURFACE-WATER QUALITY
SEDIMENT: May 1993 to November 1993,
water years 1994 to 2000 (March to December), March 2001 to current.
MISCELLANEOUS: Sediment concentration and particle size, water years 1996-99, 2002-05.
EXTREMES FOR PERIOD OF RECORD -
SUSPENDED-SEDIMENT CONCENTRATIONS: Maximum daily, 1,080 mg/L, April 18, 2013; minimum daily, 9 mg/L, December 24, 2013 and December 13, 2014.
SUSPENDED-SEDIMENT LOADS: Maximum daily, 293,000 tons, April 19, 2013; minimum daily, 140 tons, Oct. 30, 2002.